Rear-window panes of solid glass for convertibles are known. However, they require an angle frame to accommodate the material of the folding top and a rubber seal for the glass pane. When the top is folded down, however, only a spatially limited folding down of the folding-top package is possible because of the bulkiness of the angle frame, so that this package stands up relatively high. Therefore, in order to make it possible to fold down the folding top package lower, the use of rear-window panes of a flexible or transparent plastic in convertible tops is known. These have the advantage of not requiring any additional reinforcing measures, such as angle frames or the like, since they can absorb the tensile forces that arise in the material of the folding top when the latter is under tension. However, their stability is only slight. This is a disadvantage because they frequently have to be exchanged prematurely.